Terme Achilliane

Terme Achilliane is an ancient Roman bathing complex situated beneath Piazza del Duomo, dating from around the 4th century and now integrated under the later Cathedral of Sant'Agata. The main chamber is supported by four square pillars and features three arched passageways that open into parallel water basins.

The thermal baths were built around the 4th century during Emperor Constantine I's reign and were later incorporated into the Cathedral of Sant'Agata in the 11th century. This transformation illustrates how the city repurposed its ancient structures as it developed its Christian identity.

The name comes from an inscription on Lunense marble from the 5th century, now displayed at the Civic Museum in Castello Ursino. This detail connects the ancient bathing tradition to the city's broader story, preserved through artifacts in the nearby museum.

Entry is through a barrel-vaulted corridor between the cathedral foundations, accessible via a descending ramp to the right of the facade. The site requires careful footing on uneven ground, so sturdy shoes are advisable when exploring the underground passages.

The Tepidarium features an advanced heating system with air channels that distributed warmth beneath the floor, and a two-ramp staircase leading to the upper levels of the facility. This technical design reveals the sophisticated Roman engineering knowledge applied to climate control in bathing spaces.